1. Field of the Invention
This invention relates to an apparatus and a method of determining an image processing parameter used in a detection process for detecting an image of an object from a real picked-up image containing the object image, and a recording medium containing a program for determining the image processing parameter.
2. Description of the Related Art
Hitherto, an image processing apparatus, which picks up an image of an object with an image pickup unit such as a camera and detects the object from a real picked-up image containing the object image, has been used. For example, the image processing apparatus is used to detect the position of an object such as a position detection mark of a product, which is transported on a belt conveyor in a production line of a factory, and to execute the later steps using the detected position.
In the described image processing apparatus, a plurality of image processing parameters, such as a search skip width, image compression rate, etc., are used in the detection process for detecting the image of the object from the real picked-up image. In related art, an image processing apparatus, which functions as an apparatus for determining the image processing parameters, for example, obtains a correlation value for the real picked-up image with an image used as a reference for executing pattern matching, while the position of a real picked-up image to be searched is moved, and automatically determines a move distance as a search skip width when the correlation value falls to a predetermined value.
However, in the image processing apparatus of the related art, some of the image processing parameters are only determined automatically based on the correlation value, etc., and the image processing parameters cannot automatically be set for the detection accuracy of the most important performance in the detection process. Thus, the user changes the image processing parameters in various manners, actually measures the detection accuracy of the object, and corrects the image processing parameters by trial and error until the detection accuracy satisfies any desired detection accuracy. Thus, it takes a long time to optimize the image processing parameters and tuning of the image processing parameters is very intricate work.
In the case of an image processing apparatus in a manufacturing line of a factory, since a product is transported every given time, it is required that the object contained in the product be detected within a predetermined time. However, the image processing apparatus of the related art does not automatically optimize the image processing parameters for the detection processing time. Also, in this case, the user changes the image processing parameters so as to set any desired detection processing time by trial and error and thus takes a long time in correcting the image processing parameters.
Furthermore, in the case of an image processing apparatus in a factory, for example, as the brightness in the factor changes due to variations of weather conditions, time of day, illumination, and like, the image pick up conditions of the object may change. To optimize the image processing parameters in response to such change in the image pickup conditions, the user also corrects the image processing parameters by trial and error in a similar manner to that mentioned above, and thus takes a long time in optimizing the image processing parameters in response to change in the image pickup conditions; the job becomes a burden to the user.